|
Cost-effectiveness of varenicline compared to placebo as an aid to smoking cessation in patients with cardiovascular disease |
Hettle R, Wilson K, Peter T, Ezernieks J, Hackl D, Wolf C |
|
|
Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. CRD summary This study examined the cost-effectiveness of adding varenicline to counselling, compared with counselling alone, for smoking cessation in smokers with stable cardiovascular disease, who had experienced no events in the two months before treatment. The authors concluded that varenicline added to counselling was cost-effective. The cost-effectiveness methods were valid and support the reliability of the authors’ conclusions. Type of economic evaluation Cost-effectiveness analysis, cost-utility analysis Study objective This study examined the cost-effectiveness of adding varenicline to counselling, compared with counselling alone, for smoking cessation in smokers with stable cardiovascular disease (CVD), who had experienced no events in the two months before treatment. Interventions Varenicline plus counselling was compared with counselling alone. Varenicline was administered at 0.5mg once a day for three days, then 0.5mg twice a day for four days, and then 1mg twice a day for 11 weeks. Counselling consisted of 12 weekly clinic visits, lasting a maximum of 10 minutes, with a telephone call three days after the first visit. Location/setting Austria, Hungary, and Germany/primary and secondary care. Methods Analytical approach:The analysis was based on a Markov model, with a structure based on the published Benefits of Smoking Cessation on Outcomes (BENESCO) model. A lifetime horizon was considered. The authors stated that they took the perspective of the health care payer. Effectiveness data:Most of the evidence that was the same for all three countries, was from a 52-week, double-blind, placebo, randomised controlled trial (RCT). This provided the treatment effect. Other inputs were from published studies. Some incidence and prevalence statistics were from the UK general population or from the Cancer Prevention Study II, which was a large longitudinal study of smoking-related mortality in the USA. Smoking prevalence was from country-specific databases. The rates of continuous abstinence from week nine to week 52, which were verified by the measurement of expired air carbon monoxide, were the key inputs for the model. Monetary benefit and utility valuations:The utility values were from published sources. Measure of benefit:Life-years and quality-adjusted life-years (QALYs) were the summary benefit measures. A 3% annual discount rate was applied. Cost data:The economic analysis included the cost of the smoking cessation intervention and the costs of disease management, including stroke, chronic heart disease, peripheral vascular disease, lung cancer, mouth cancer, and chronic obstructive pulmonary disease. The quantities of resources used for varenicline and counselling were from the RCT that provided the treatment effect, and the unit costs were from official sources in each country. The cost of disease management came from various sources in each country, including national data registries and published studies. Where costs were not available for a country, the ratio of other costs between this and another country was applied. The costs were in Euros (EUR) and were discounted at an annual rate of 3%. The price year was 2010. Analysis of uncertainty:The uncertainty was investigated in disease subgroup analyses, and in one-way and probabilistic sensitivity analyses. The univariate sensitivity analyses considered variations in the time horizon and the costs of disease management. The probabilistic sensitivity analysis generated cost-effectiveness acceptability curves. A societal perspective was adopted, in the sensitivity analysis, and the costs of a premature death were based on the average earnings in each country. Results In a hypothetical cohort of 1,000 smokers, over a lifetime, from a health care perspective, in Austria, the expected total costs were EUR 17,730,771 with varenicline and EUR 16,970,528 with placebo. The life-years were 7,175 with varenicline and 6,991 with placebo. The QALYs were 5,316 with varenicline and 5,172 with placebo. In Hungary, the costs were EUR 6,110,250 with varenicline, and EUR 5,771,339 with placebo The life-years were 6,094 with varenicline, and 5,958 with placebo. The QALYs were 4,511 with varenicline, and 4,405 with placebo. In Germany, the costs were EUR 32,278,318 with varenicline, and EUR 31,423,185 with placebo. The life-years were 7,078 with varenicline, and 6,891 with placebo. The QALYs were 5,243 with varenicline, and 5,098 with placebo. The incremental cost per life-year gained with varenicline was EUR 4,112 in Austria, EUR 2,507 in Hungary, and EUR 4,567 in Germany. The incremental cost per QALY gained with varenicline was EUR 5,278 in Austria, EUR 3,183 in Hungary, and EUR 5,867 in Germany. From a societal perspective, varenicline was dominant, as it was more effective and less expensive, in all countries. The deterministic sensitivity analysis confirmed that the findings were robust. In the probabilistic analysis, varenicline remained cost-effective in all simulations under a threshold of EUR 12,500 per QALY gained. The subgroup analysis showed that varenicline was more cost-effective in patients with chronic heart disease than in those with stroke or peripheral vascular disease. Authors' conclusions The authors concluded that varenicline added to counselling was cost-effective, compared with placebo and counselling, in patients with stable disease. CRD commentary Interventions:The selection of the comparators was appropriate as the proposed drug treatment was compared with counselling alone, which was the usual care for smokers with cardiovascular disease. The dosage of varenicline was based on that used in the RCT. Effectiveness/benefits:The treatment effect was from a double-blind, placebo-controlled RCT, which should ensure high internal validity. Other data were from valid sources, but no country-specific estimates were available for some parameters. The extensive sensitivity analysis showed that the results were robust to variations in these items. The clinical analysis was generally conducted satisfactorily. QALYs were an appropriate benefit measure for the patient population and they allow comparisons with other disease areas. No details on the sources for the utility weights were provided. Costs:The types of costs were appropriate for each perspective. The unit costs and quantities of resources were not presented separately and most of the costs were reported as category totals. The resource use was from the RCT, which was conducted in the USA; the relevance of these values to each country was not discussed. The costs were from country-specific sources, but these were not clearly described. The impact of variations in selected costs was tested in the sensitivity analyses. The price year was explicitly reported, which allows reflation exercises. Currency conversions were appropriately performed. Analysis and results:The results were clearly reported for the main analysis and the sensitivity analyses. Clear and extensive details on the model assumptions and clinical pathways were reported. An incremental approach was appropriately used to synthesise the costs and benefits of the strategies. Deterministic and probabilistic sensitivity analyses were carried out, but limited information on the methods underlying the probabilistic analysis was provided. The authors reported that published cost-effectiveness analyses, conducted in other European countries, had found similar results, and it is likely that the findings are transferable to other developed countries. Concluding remarks:The cost-effectiveness methods were valid and support the reliability of the authors’ conclusions. Funding Funded by Pfizer Inc, manufacturer of varenicline. Bibliographic details Hettle R, Wilson K, Peter T, Ezernieks J, Hackl D, Wolf C. Cost-effectiveness of varenicline compared to placebo as an aid to smoking cessation in patients with cardiovascular disease. Open Pharmacoeconomics and Health Economics Journal 2012; 4(1): 8-17 Indexing Status Subject indexing assigned by CRD MeSH Benzazepines; Cardiovascular Diseases; Cost-Benefit Analysis; Humans; Markov Chains; Nicotinic Agonists; Quality-Adjusted Life Years; Quinoxalines; Smoking; Smoking Cessation AccessionNumber 22012017049 Date bibliographic record published 13/06/2012 Date abstract record published 18/12/2012 |
|
|
|